Any time the editor is used, the following debugging message is displayed:
However, this is not a problem in the editor or something that editor has under control. It is actually the existing Moodle core code that produces that huge file picker options and passes it to the editor. See $fpoptions at https://github.com/moodle/moodle/blob/master/lib/form/editor.php#L391
So the problem here is that the form element "editor" generates too big file picker options.